1 files changed, 120 insertions, 0 deletions
diff --git a/trunk/infrastructure/rhino1_7R1/src/org/mozilla/javascript/UniqueTag.java b/trunk/infrastructure/rhino1_7R1/src/org/mozilla/javascript/UniqueTag.java
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+++ b/trunk/infrastructure/rhino1_7R1/src/org/mozilla/javascript/UniqueTag.java
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+/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ *
+ * ***** BEGIN LICENSE BLOCK *****
+ * Version: MPL 1.1/GPL 2.0
+ *
+ * The contents of this file are subject to the Mozilla Public License Version
+ * 1.1 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ * http://www.mozilla.org/MPL/
+ *
+ * Software distributed under the License is distributed on an "AS IS" basis,
+ * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
+ * for the specific language governing rights and limitations under the
+ * License.
+ *
+ * The Original Code is Rhino code, released
+ * May 6, 1999.
+ *
+ * The Initial Developer of the Original Code is
+ * Netscape Communications Corporation.
+ * Portions created by the Initial Developer are Copyright (C) 1997-1999
+ * the Initial Developer. All Rights Reserved.
+ *
+ * Contributor(s):
+ *   Igor Bukanov
+ *
+ * Alternatively, the contents of this file may be used under the terms of
+ * the GNU General Public License Version 2 or later (the "GPL"), in which
+ * case the provisions of the GPL are applicable instead of those above. If
+ * you wish to allow use of your version of this file only under the terms of
+ * the GPL and not to allow others to use your version of this file under the
+ * MPL, indicate your decision by deleting the provisions above and replacing
+ * them with the notice and other provisions required by the GPL. If you do
+ * not delete the provisions above, a recipient may use your version of this
+ * file under either the MPL or the GPL.
+ *
+ * ***** END LICENSE BLOCK ***** */
+
+package org.mozilla.javascript;
+
+import java.io.Serializable;
+
+/**
+ * Class instances represent serializable tags to mark special Object values.
+ * <p>
+ * Compatibility note: under jdk 1.1 use
+ * org.mozilla.javascript.serialize.ScriptableInputStream to read serialized
+ * instances of UniqueTag as under this JDK version the default
+ * ObjectInputStream would not restore them correctly as it lacks support
+ * for readResolve method
+ */
+public final class UniqueTag implements Serializable
+{
+    static final long serialVersionUID = -4320556826714577259L;
+
+    private static final int ID_NOT_FOUND    = 1;
+    private static final int ID_NULL_VALUE   = 2;
+    private static final int ID_DOUBLE_MARK  = 3;
+
+    /**
+     * Tag to mark non-existing values.
+     */
+    public static final UniqueTag
+        NOT_FOUND = new UniqueTag(ID_NOT_FOUND);
+
+    /**
+     * Tag to distinguish between uninitialized and null values.
+     */
+    public static final UniqueTag
+        NULL_VALUE = new UniqueTag(ID_NULL_VALUE);
+
+    /**
+     * Tag to indicate that a object represents "double" with the real value
+     * stored somewhere else.
+     */
+    public static final UniqueTag
+        DOUBLE_MARK = new UniqueTag(ID_DOUBLE_MARK);
+
+    private final int tagId;
+
+    private UniqueTag(int tagId)
+    {
+        this.tagId = tagId;
+    }
+
+    public Object readResolve()
+    {
+        switch (tagId) {
+          case ID_NOT_FOUND:
+            return NOT_FOUND;
+          case ID_NULL_VALUE:
+            return NULL_VALUE;
+          case ID_DOUBLE_MARK:
+            return DOUBLE_MARK;
+        }
+        throw new IllegalStateException(String.valueOf(tagId));
+    }
+
+// Overridden for better debug printouts
+    public String toString()
+    {
+        String name;
+        switch (tagId) {
+          case ID_NOT_FOUND:
+            name = "NOT_FOUND";
+            break;
+          case ID_NULL_VALUE:
+            name = "NULL_VALUE";
+            break;
+          case ID_DOUBLE_MARK:
+            name = "DOUBLE_MARK";
+            break;
+          default:
+            throw Kit.codeBug();
+        }
+        return super.toString()+": "+name;
+    }
+
+}
+